Light Emitting Panel and Lighting Apparatus

ABSTRACT

According to one embodiment, a light emitting panel includes: an organic layer including a light emitting layer; a transparent first electrode provided on one surface of the organic layer; and a second electrode provided on the other surface of the organic layer. The second electrode includes an opaque first metal film section and a second metal film section having a film thickness thinner than a film thickness of the first metal film section and light transparency higher than light transparency of the first metal film section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2013-136790, filed on Jun. 28, 2013; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a light emitting paneland a lighting apparatus.

BACKGROUND

As a light source of a lighting apparatus, an Organic Light-EmittingDiode (OLED) using organic electroluminescence is proposed. In thetypical OLED, a transparent electrode such as Indium Tin Oxide (ITO) isused as an electrode on a side of a light take-out surface and an opaquemetal electrode such as aluminum or silver is used as an electrode on aside of a back surface. Light that is radiated from a light emittinglayer and directed to the side of the back surface is reflected in themetal electrode and then is taken out from the side of the transparentelectrode. In this structure, the light does not come around the side ofthe back surface and a space thereof is seen as dark.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematic views of a light emitting panel of a firstembodiment.

FIGS. 2A and 2B are schematic views of a lighting apparatus using thelight emitting panel of the first embodiment.

FIGS. 3A and 3B are schematic views of another specific example of thelight emitting panel of the first embodiment.

FIGS. 4A and 4B are schematic views of a lighting apparatus of a secondembodiment.

FIGS. 5A and 5B are schematic views of a lighting apparatus of a thirdembodiment.

FIGS. 6A and 6B are schematic views of a lighting apparatus of a fourthembodiment.

FIG. 7 is a schematic view of a light emitting panel used for thelighting apparatus of the fourth embodiment.

FIG. 8 is a graph illustrating a relationship between a film thicknessof an Ag film and a transmission.

DETAILED DESCRIPTION

According to an embodiment, a light emitting panel includes an organiclayer having a light emitting layer; a transparent first electrodeprovided on one surface of the organic layer; and a second electrodeprovided on the other surface of the organic layer. The second electrodehas an opaque first metal film section and a second metal film sectionhaving a film thickness thinner than a film thickness of the first metalfilm section and light transparency higher than light transparency ofthe first metal film section.

Hereinafter, an embodiment will be described with reference to thedrawings. Moreover, the same reference numerals are given to the sameelements in each of the drawings.

First Embodiment

FIG. 1A is a schematic cross-sectional view of a light emitting panel 11of a first embodiment.

The light emitting panel 11 has an organic layer 30, a first electrode21 that is provided on one surface of the organic layer 30, and a secondelectrode 22 that is provided on the other surface of the organic layer30. The organic layer 30, the first electrode 21 and the secondelectrode 22 are supported on a substrate 20. The organic layer 30includes a light emitting layer 32.

The substrate 20 is a transparent substrate and is, for example, a glasssubstrate. Otherwise, the substrate 20 may be a transparent resinsubstrate.

In the specification, the term “transparent” refers to havingtransparency to the light emitted from the light emitting layer 32 andis not limited to light transmission of 100%. Particularly, it meansthat the transmission is 20% or more and is preferably 30% or more at awavelength of 550 nm. The light emitting layer 32 emits visible light.Further, the term “transparent” also refers to having transparency to atransmitting signal of a remote controller or to detection target lightof a human sensor or the like. For example, the term “transparent” alsorefers to having transparency to infrared radiation.

The term “opaque” refers to having a light shielding property or areflective property to the light emitted from the light emitting layer32. The term “opaque” is not limited to the transmission of 0% of thelight emitted from the light emitting layer 32 and also refers to a casewhere the transmission is relatively lower than that of a transparentregion. Particularly, it means that the transmission is 20% or less andis preferably 15% or less at the wavelength of 550 nm.

As illustrated in FIG. 1A, the first electrode 21 is provided on thesubstrate 20. The first electrode 21 is a transparent electrode and, forexample, is made of Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), aconductive polymer or the like.

The organic layer 30 is provided on the first electrode 21. The organiclayer 30 includes the light emitting layer 32, a hole transport layer 31and an electron transport layer 33. The hole transport layer 31 isprovided on the first electrode 21, the light emitting layer 32 isprovided on the hole transport layer 31, and the electron transportlayer 33 is provided on the light emitting layer 32.

The second electrode 22 is provided on the electron transport layer 33.Further, the second electrode 22 is also provided on a part of thesurface of the substrate 20. The second electrode 22 is continuouslyprovided from the surface of the substrate 20 to an upper surface of theorganic layer 30 so as to coat a step between the surface of thesubstrate 20 and the upper surface of the organic layer 30.

An insulation film 26 is provided between the second electrode 22 and aside surface of the organic layer 30, and between the second electrode22 and an end portion of the first electrode 21.

A transparent sealing member 24 is superimposed on the substrate 20through a sealing body 25. A laminated body including the organic layer30, the first electrode 21 and the second electrode 22 is sealed betweenthe substrate 20 and the transparent sealing member 24.

The sealing member 24 is a glass substrate or a transparent resin. Thesealing body 25 is, for example, made of resin and is continuouslyprovided around a region between the substrate 20 and the sealing member24.

Next, the second electrode 22 will be described in detail. FIG. 1B is aschematic top plan view of the second electrode 22 on the organic layer30.

The second electrode 22 is a metal film and has a first metal filmsection 22 a and a second metal film section 22 b. The first metal filmsection 22 a and the second metal film section 22 b are integrallyprovided with the same metal film and have relatively different filmthicknesses.

The film thickness of the second metal film section 22 b is thinner thanthat of the first metal film section 22 a. The first metal film section22 a has a thickness through which the light emitted from the lightemitting layer 32 is hardly transmitted and a region in which the firstmetal film section 22 a is provided is an opaque region.

Since the second metal film section 22 b is thinner than the first metalfilm section 22 a, the light transmission thereof is higher than that ofthe first metal film section 22 a and the second metal film section 22 btransmits the light emitted from the light emitting layer 32. A regionin which the second metal film section 22 b is provided is a transparentregion.

The second electrode 22 is, for example, a silver (Ag) film or analuminum (Al) film.

FIG. 8 is a graph illustrating a relationship between a film thicknessand the light transmission of the Ag film.

A horizontal axis refers to the wavelength (nm) and a vertical axisrefers to the transmission (%).

For example, the Ag film can be a transparent film to the visible lightby the film thickness of the Ag film being 20 nm or less. Fromexperience, if the film thickness of the Ag film is 30 nm or less, thetransmission can be 20% or more at the wavelength of 550 nm or less.That is, the film thickness of the second metal film section 22 b ispreferably 30 nm or less. Moreover, a function as an electrode forsupplying a current to the light emitting layer while diffusing in aplane direction is sufficient as long as the film thickness is 10 nm. Onthe other hand, the film thickness of the first metal film section 22 ais preferably 30 nm or more. However, since the function as theelectrode does not vary if the film thickness is 200 nm or more, thefilm thickness of the first metal film section 22 a is preferably 200 nmor less.

Further, the first metal film section 22 a which is relatively thick hasa reflective property to the light emitted from the light emitting layer32 higher than that of the second metal film section 22 b. Therefore,the light that is emitted from the light emitting layer 32 and isdirected to the side of the second electrode 22 is reflected in thefirst metal film section 22 a of the second electrode 22 and is takenout on the side of the transparent substrate 20 through the firstelectrode 21 that is the transparent electrode.

As illustrated in FIG. 1B, the second metal film section 22 b of thesecond electrode 22 is provided on the side of an outer periphery of theorganic layer 30 and the first metal film section 22 a is providedinside the second metal film section 22 b. The first metal film section22 a is provided in a region including a center portion of the organiclayer 30 in the plane direction and the second metal film section 22 bcontinuously encloses the periphery of the first metal film section 22a.

Next, FIG. 2A is a schematic view of a lighting apparatus 1 using thelight emitting panel 11 illustrated in FIG. 1A.

An apparatus body 40 is provided on the side of a back surface (on theside of the sealing member 24) in the light emitting panel 11. Theapparatus body 40 holds the light emitting panel 11.

For example, a ceiling surface is positioned on the upper side in FIG.2A. The lighting apparatus 1 is attached to the ceiling surface throughthe apparatus body 40 in a state where a light take-out surface (asurface on the side of the substrate 20) of the light emitting panel 11is directed downward on the opposite side to the ceiling surface.

FIG. 2B is a schematic plan view of the lighting apparatus 1.

An opaque region 80 in which the first metal film section 22 a of thesecond electrode 22 is provided is represented by cross-hatching in FIG.2B. A transparent region 90 in which the second metal film section 22 bof the second electrode 22 is provided is formed in a periphery of theopaque region 80. The transparent region 90 continuously encloses theperiphery of the opaque region 80.

The apparatus body 40 is provided by being superimposed on the opaqueregion 80. An external size of the apparatus body 40 is sized to fitwithin the opaque region 80 and the apparatus body 40 is notsuperimposed on the transparent region 90. Otherwise, a part of theapparatus body 40 may protrude on the side of the transparent region 90from the opaque region 80. In any event, at least a part of thetransparent region 90 is not covered by the apparatus body 40 and it ispossible to take out the light from the transparent region 90 to theside of the back surface (the side of the ceiling).

The first electrode 21 functions as an anode and the second electrode 22functions as a cathode in an OLED. If a relatively high potential isapplied to the first electrode 21 and a relatively low potential isapplied to the second electrode 22, holes are injected from the firstelectrode 21 into the light emitting layer 32 through the hole transportlayer 31 and electrons are injected from the second electrode 22 intothe light emitting layer 32 through the electron transport layer 33.Then, the holes and the electrons are recombined in the light emittinglayer 32 and the light emitting layer 32 emits the light with energygenerated at this time.

The light emitted from the light emitting layer 32 is directed to theside of the first electrode 21 and to the side of the second electrode22. The light directed to the side of the first electrode 21 istransmitted through the first electrode 21 that is the transparentelectrode and the transparent substrate 20, and is radiated to the sideof a main light take-out surface on the opposite side to the ceilingsurface.

The light directed from the light emitting layer 32 to the side of thesecond electrode 22 is reflected in the first metal film section 22 athat is the opaque region and is taken out to the side of the substrate20. Thus, it is possible to increase a light amount radiated to the sideof the main light take-out surface.

One-side emission is performed in the opaque region in which the firstmetal film section 22 a is provided. By contrast, both-side emission isperformed in the transparent region in which the second metal filmsection 22 b is provided.

That is, a part of the light directed from the light emitting layer 32to the side of the second electrode 22 is taken out to the side of theceiling surface by being transmitted through the second metal filmsection 22 b. At this time, since the apparatus body 40 does not coverthe transparent region 90 in which the second metal film section 22 b isprovided, the light directed to the side of the ceiling surface is notblocked by the apparatus body 40.

That is, according to the embodiment, it is possible to take out thelight to the side of the back surface and to illuminate an installationsurface such as the ceiling surface without providing a separate lightsource on the side of the back surface of the lighting apparatus 1.Therefore, it is possible to increase a feeling of brightness of a spacein which a user is located by an indirect lighting effect and it ispossible to create a sense of an extent or a depth of the space.

Moreover, it is possible for the light to be illuminated on the side ofthe ceiling surface by a both-side emission structure in which an entireregion of the second electrode 22 on the side of the back surface is thetransparent electrode. However, for the both-side emission, half of thelight emission energy is lost by escaping to the opposite side to themain light take-out surface.

By contrast, according to the embodiment, the transparent region 90 (thesecond metal film section 22 b) is not in the entire region of theorganic layer 30 on the side of the back surface but is a part thereof.The first metal film section 22 a that functions as a reflective metalis also provided on the side of the back surface. Therefore, accordingto the embodiment, it is also possible to illuminate the side of theinstallation surface such as the ceiling surface while suppressingreduction of the light amount radiating to the side of the main lighttake-out surface. Moreover, in order to increase a yield property whileobtaining a sufficient light amount on the side of the main lighttake-out surface, the area of the opaque region is preferably 0.05 timesto 4 times of the area of the transparent region. That the area of theopaque region be one time, that is, equal to the area of the transparentregion is most suitable.

In addition, in order to make a part of the second electrodetransparent, a part of the second electrode may be made by a transparentelectrode such as ITO or IZO. However, ITO or IZO is typically formed bya sputtering method and there is a concern that the upper surface of theorganic layer 30 may be damaged when sputtering is performed.

By contrast, according to the embodiment, the transparent section andthe opaque section are mixed in the second electrode 22 by thedifference of the film thickness of the metal film. For example, themetal film such as Ag or Al is formed on the upper surface of theorganic layer 30 by a vapor depositing method. Thus, when forming thesecond electrode 22, the organic layer 30 is not damaged.

For example, first, a thin metal film is formed on the entirety of theupper surface of the organic layer 30. Thereafter, the metal film isfurther deposited only on a portion to have thick film thickness using amask. Therefore, it is possible to form the metal film on the uppersurface of the organic layer 30 by generating the difference in the filmthickness.

Moreover, when forming the thin film and when forming additional film tothicken the thickness, it is possible to form the first metal filmsection 22 a and the second metal film section 22 b of differentmaterials by changing a material of an vapor depositing source.

Further, the second metal film section 22 b (the transparent region 90)has transparency to infrared radiation. Thus, it is possible to remotelycontrol the lighting apparatus 1 by providing a receiving section of atransmitting signal of the remote controller that operates the lightingapparatus 1 on the back side of the transparent region 90 in the lightemitting panel 11. Otherwise, it is also possible to provide a receivingsection of the human sensor, a brightness sensor or the like on the backside of the transparent region 90.

It is possible to reduce a planar size of the entirety of the lightingapparatus 1 by providing the receiving section described above in aposition superimposed on the light emitting panel 11 without providingthe receiving section on the outside of an end portion of the lightemitting panel 11.

A planar layout of the first metal film section 22 a and the secondmetal film section 22 b in the second electrode 22 is not limited to thelayout illustrated in FIG. 1B.

FIG. 3A is a schematic cross-sectional view of another specific exampleof the light emitting panel 11.

FIG. 3B is a schematic top plan view of the second electrode 22 on theorganic layer 30 illustrated in FIG. 3A.

The first metal film section 22 a of the second electrode 22 which isrelatively thick is provided on the side of the outer periphery of theorganic layer 30 and the second metal film section 22 b which isrelatively thin is provided inside the first metal film section 22 a.The second metal film section 22 b is provided in a region including thecenter portion of the organic layer 30 in the plane direction and thefirst metal film section 22 a continuously surrounds the periphery ofthe second metal film section 22 b.

Otherwise, for the light emitting panel 11 illustrated in FIG. 4Bdescribed below, the first metal film section 22 a (the opaque region80) and the second metal film section 22 b (the transparent region 90)may be laid out so as to divide in half a square-shaped plane region ofthe organic layer 30.

In the transparent region 90 in which the second metal film section 22 bis provided, the light directed from the light emitting layer 32 to theside of the back surface is transmitted through the second metal filmsection 22 b and is not reflected on the side of the substrate 20 (onthe side of the main light take-out surface). Then, it is possible tocompensate for the light amount radiating to the side of the main lighttake-out surface (the side of the substrate 20) in the transparentregion (the both-side emission region) 90 by making a voltage appliedbetween the second metal film section 22 b and the first electrode 21greater than that applied between the first metal film section 22 a andthe first electrode 21.

It is possible to apply different voltages to the transparent region 90and the opaque region 80 by patterning the second electrode 22 byseparating the first metal film section 22 a and the second metal filmsection 22 b.

Further, the film thickness in the second electrode 22 is not limited tobe changed in a single stage and may be changed in multiple stages. Inaddition, the film thickness of a boundary region between the firstmetal film section 22 a and the second metal film section 22 b may becontinuously changed or may be changed in multiple stages. In this case,it is possible to reduce difference in the brightness between the opaqueregion 80 and the transparent region 90.

Second Embodiment

FIG. 4A is a schematic view of a lighting apparatus 2 of a secondembodiment.

FIG. 4B is a schematic plan view of the lighting apparatus 2 of thesecond embodiment.

The lighting apparatus 2 of the second embodiment has a plurality offirst light emitting panels 11 and a plurality of second light emittingpanels 12 which are arranged in the tiled arrangement. The plurality offirst light emitting panels 11 and the plurality of second lightemitting panels 12 are held on the apparatus body 40.

For example, the ceiling surface is positioned on the upper side in FIG.4A. The lighting apparatus 2 is attached to the ceiling surface throughthe apparatus body 40 in a state where the first light emitting panel 11and the second light emitting panel 12 are directed downward on theopposite side to the ceiling surface.

The opaque region is represented by cross-hatching in FIG. 4B.

The first light emitting panel 11 has the same structure as the lightemitting panel 11 of the first embodiment. However, in the first lightemitting panel 11 of the second embodiment, the first metal film section22 a (the opaque region 80) and the second metal film section 22 b (thetransparent region 90) are laid out so as to divide in half thesquare-shaped plane region of the organic layer 30.

The second light emitting panel 12 is also the light emitting panelhaving the OLED structure using organic electroluminescence. That is,the second light emitting panel 12 has a structure in which the organiclayer including the light emitting layer is sandwiched between the firstelectrode and the second electrode.

In the second light emitting panel 12, similar to the first lightemitting panel 11, the first electrode is provided on the side of thetransparent substrate and is transparent. The second electrode is themetal film. The second electrode thereof has a sufficient thicknessthroughout the entire region on the upper surface of the organic layerand is opaque. That is, the second light emitting panel 12 is the opaquelight emitting panel of the one-side emission type where the side of theback surface on which the second electrode is provided in the organiclayer is opaque.

The side of the first electrode (the side of the substrate) with thefirst light emitting panel 11 and the second light emitting panel 12 isthe main light take-out surface, and the apparatus body 40 is providedon the side of the back surface (the side of the second electrode) onthe other side thereof.

As illustrated in FIG. 4B, the light emitting surface on which theplurality of first light emitting panels 11 and the plurality of secondlight emitting panels 12 are formed by being combined in the tiledarrangement is, for example, formed in a rectangular shape. The firstlight emitting panels 11 are disposed in both ends of the light emittingsurface in a lateral direction and the first light emitting panels 11are disposed along the light emitting surface in a longitudinaldirection. The second light emitting panels 12 are disposed between thefirst light emitting panels 11 of both ends in the lateral direction.

In the first light emitting panel 11, the transparent region 90 isdirected to the outside in the lateral direction. The opaque region 80in the first light emitting panel 11 is adjacent to the second lightemitting panel 12 that is the opaque one-side emission panel. Then, theopaque region 80 illustrated in cross-hatching in FIG. 4B is formed bycombining the opaque region 80 of the first light emitting panel 11 andthe second light emitting panel 12.

In the entirety of the lighting apparatus 2, the transparent region 90(the both-side emission region) is disposed in both ends of the lightemitting surface in the lateral direction and the opaque region 80 (theone-side emission region) is spread between the transparent regions 90of both ends thereof.

The apparatus body 40 is provided by being superimposed on the opaqueregion 80. The external size of the apparatus body 40 is sized to fitwithin the opaque region 80 and the apparatus body 40 is notsuperimposed on the transparent region 90. Otherwise, a part of theapparatus body 40 may protrude from the opaque region 80 into the sideof the transparent region 90. In any event, at least a part of thetransparent region 90 is not covered by the apparatus body 40 and it ispossible to take out the light on the side of the back surface (the sideof the ceiling) from the transparent region 90.

In the transparent region 90, similar to the first embodiment, a part ofthe light directed from the light emitting layer 32 to the side of thesecond electrode 22 is taken out to the side of the ceiling surface bybeing transmitted through the second metal film section 22 b. At thistime, since the apparatus body 40 does not cover the transparent region90, the light directed to the side of the ceiling surface is not blockedby the apparatus body 40.

Therefore, according to the second embodiment, it is possible to takeout the light to the side of the back surface and to illuminate theinstallation surface such as the ceiling surface without providing aseparate light source on the side of the back surface of the lightingapparatus 2.

Further, in the opaque region 80, the light directed to the side of theback surface (the side of the ceiling) is taken out from the main lighttake-out surface of the side of the first electrode by being reflectedin the second electrode.

Therefore, according to the second embodiment, it is also possible toilluminate the side of the installation surface such as the ceilingsurface while suppressing reduction of the light amount radiating to theside of the main light take-out surface.

Further, the transparent region 90 has transparency to infraredradiation. Thus, it is possible to remotely control the lightingapparatus 2 by providing the receiving section of the transmittingsignal of the remote controller that operates the lighting apparatus 2on the back side of the transparent region 90. Otherwise, it is alsopossible to provide the receiving section of the human sensor, thebrightness sensor or the like on the back side of the transparent region90.

It is possible to reduce the planar size of the entirety of the lightingapparatus 2 by providing the receiving section described above in theposition superimposed on the light emitting panel without providing thereceiving section on the outside of the end portion of the lightemitting panel.

Third Embodiment

FIG. 5A is a schematic view of a lighting apparatus 3 of a thirdembodiment.

FIG. 5B is a schematic plan view of the lighting apparatus 3 of thethird embodiment.

The lighting apparatus 3 of the third embodiment has a plurality oftransparent light emitting panels 13 and a plurality of opaque lightemitting panels 12 which are arranged in the tiled arrangement. Theplurality of transparent light emitting panels 13 and the plurality ofopaque light emitting panels 12 are held on the apparatus body 40.

For example, the ceiling surface is positioned on the upper side in FIG.5A. The lighting apparatus 3 is attached to the ceiling surface throughthe apparatus body 40 in a state where the transparent light emittingpanel 13 and the opaque light emitting panel 12 are directed downward onthe opposite side to the ceiling surface.

The transparent light emitting panel 13 and the opaque light emittingpanel 12 are the light emitting panel having the OLED structure usingorganic electroluminescence. That is, the transparent light emittingpanel 13 and the opaque light emitting panel 12 have the structure inwhich the organic layer including the light emitting layer is sandwichedbetween the first electrode and the second electrode.

In the transparent light emitting panel 13 and the opaque light emittingpanel 12, similar to the light emitting panel 11 of the firstembodiment, the first electrode is provided on the side of thetransparent substrate and is transparent.

In the transparent light emitting panel 13, the second electrode is thetransparent electrode. Otherwise, similar to the second metal filmsection 22 b of the light emitting panel 11 of the first embodiment, thesecond electrode is the thin metal film having light transparency. Thatis, the transparent light emitting panel 13 is the both-side emissionpanel in which the sides of both surfaces of the organic layer aretransparent.

In the opaque light emitting panel 12, the second electrode is the metalfilm. The second electrode thereof has a sufficient thickness throughoutthe entire region on the upper surface of the organic layer and isopaque. That is, the opaque light emitting panel 12 is the opaque lightemitting panel of the one-side emission type where the side of the backsurface on which the second electrode is provided in the organic layeris opaque.

The side of the first electrode (the side of the substrate) with thetransparent light emitting panel 13 and the opaque light emitting panel12 is the main light take-out surface, and the apparatus body 40 isprovided on the side of the back surface (the side of the secondelectrode) on the other side thereof.

As illustrated in FIG. 5B, the light emitting surface on which theplurality of transparent light emitting panels 13 and the plurality ofopaque light emitting panels 12 are formed by being combined in thetiled arrangement is, for example, formed in the rectangular shape. Thetransparent light emitting panels 13 are disposed in both ends of thelight emitting surface in the lateral direction and the transparentlight emitting panels 13 are disposed along the light emitting surfacein the longitudinal direction. The opaque light emitting panels 12 aredisposed between the transparent light emitting panels 13 of both endsin the lateral direction.

The region in which the opaque light emitting panels 12 are arranged isthe opaque region 80 illustrated in cross-hatching in FIG. 5B.

In the entirety of the lighting apparatus 3, the transparent lightemitting panels 13 (the transparent region 90) are disposed in both endsof the light emitting surface in the lateral direction and the opaqueregion 80 (the one-side emission region) is spread between thetransparent regions 90 of both ends thereof.

The apparatus body 40 is provided by being superimposed on the opaqueregion 80. The external size of the apparatus body 40 is sized to fitwithin the opaque region 80 and the apparatus body 40 is notsuperimposed on the transparent region 90. Otherwise, a part of theapparatus body 40 may protrude from the opaque region 80 into the sideof the transparent region 90. In any event, at least a part of thetransparent region 90 is not covered by the apparatus body 40 and it ispossible to take out the light on the side of the back surface (on theside of the ceiling) from the transparent region 90.

In the transparent region 90, the light directed from the light emittinglayer to the side of the second electrode is taken out to the side ofthe ceiling surface by being transmitted through the second electrode.At this time, since the apparatus body 40 does not cover the transparentregion 90, the light directed to the side of the ceiling surface is notblocked by the apparatus body 40.

Therefore, according to the third embodiment, it is possible to take outthe light to the side of the back surface and to illuminate theinstallation surface such as the ceiling surface without providing aseparate light source on the side of the back surface of the lightingapparatus 3.

Further, in the opaque region 80, the light directed to the side of theback surface (the side of the ceiling) is taken out from the main lighttake-out surface of the side of the first electrode by being reflectedin the second electrode.

Therefore, according to the third embodiment, it is also possible toilluminate the side of the installation surface such as the ceilingsurface while suppressing reduction of the light amount radiating to theside of the main light take-out surface.

Further, the transparent region 90 has transparency to infraredradiation. Thus, it is possible to remotely control the lightingapparatus 3 by providing the receiving section of the transmittingsignal of the remote controller that operates the lighting apparatus 3on the back side of the transparent region 90. Otherwise, it is alsopossible to provide the receiving section of the human sensor, thebrightness sensor or the like on the back side of the transparent region90.

It is possible to reduce the planar size of the entirety of the lightingapparatus 3 by providing the receiving section described above in theposition superimposed on the light emitting panel without providing thereceiving section on the outside of the end portion of the lightemitting panel.

Fourth Embodiment

FIG. 6A is a schematic view of a lighting apparatus 4 of a fourthembodiment.

FIG. 6B is a schematic plan view of the lighting apparatus 4 of thefourth embodiment.

The lighting apparatus 4 of the fourth embodiment has the plurality ofopaque light emitting panels 12 and at least one sheet of a transparentlight emitting panel 14 which are arranged in the tiled arrangement. Theopaque light emitting panels 12 and the transparent light emitting panel14 are held on the apparatus body 40.

For example, the ceiling surface is positioned on the upper side in FIG.6A. The lighting apparatus 4 is attached to the ceiling surface throughthe apparatus body 40 in a state where the opaque light emitting panels12 and the transparent light emitting panel 14 are directed downward onthe opposite side to the ceiling surface.

The opaque light emitting panels 12 and the transparent light emittingpanel 14 are the light emitting panel having the OLED structure usingthe organic electroluminescence.

The opaque light emitting panels 12 have the same structure as theopaque light emitting panel of the embodiments described above. That is,in the opaque light emitting panel 12, the first electrode is providedon the side of the transparent substrate and is transparent. The secondelectrode is the metal film. The second electrode thereof has asufficient thickness throughout the entire region on the upper surfaceof the organic layer and is opaque. That is, the opaque light emittingpanel 12 is the opaque light emitting panel of the one-side emissiontype where the side of the back surface on which the second electrode isprovided in the organic layer is opaque.

FIG. 7 is a schematic cross-sectional view of the transparent lightemitting panel 14. As described below, the transparent light emittingpanel 14 has transparency while performing the one-side emission.

The first electrode 21 is provided on the transparent substrate 20 suchas the glass substrate or the resin substrate. The first electrode 21 isthe transparent electrode such as ITO or IZO. The organic layer 30 isprovided on the first electrode 21 thereof.

The organic layer 30 has the hole transport layer 31 provided on thefirst electrode 21, the light emitting layer 32 provided on the holetransport layer 31 and the electron transport layer 33 provided on thelight emitting layer 32.

A second electrode 52 is provided on the upper surface (on the electrontransport layer 33) of the organic layer 30. The second electrode 52 isan opaque metal electrode with respect to the light emitted from thelight emitting layer 32. The second electrode 52 is linearly formedextending in a direction passing through a paper plane in FIG. 7. Aplurality of linear second electrodes 52 are arranged on the organiclayer 30 at intervals between each other.

The light emitting layer 32 emits the light in the region sandwichedbetween the first electrode 21 and the linear second electrodes 52. Thelight emitted between the first electrode 21 and the second electrodes52 and directed to the side of the second electrodes 52 is reflected inthe second electrodes 52 and then is taken out to the side of thesubstrate 20. Further, the light is not emitted in a region (a regionbetween the adjacent second electrodes 52) in which the secondelectrodes 52 are not provided. Therefore, the light emitting panelillustrated in FIG. 7 is the one-side emission panel.

Further, a portion in which the second electrodes 52 are not provided onthe side of the back surface (the upper surface in FIG. 7) in theorganic layer 30 has light transparency and is transparent. Therefore,it is possible for the transmitting signal of the remote controller orthe detection target light of the human sensor or the light sensor to betransmitted from the side of the substrate 20 to the side of the backsurface.

That is, it is possible for various receiving sections disposed on theside of the back surface of the transparent light emitting panel 14 toreceive external information through the transparent light emittingpanel 14.

The side of the first electrode (the side of the substrate) with theopaque light emitting panel 12 and the transparent light emitting panel14 is the light take-out surface and the apparatus body 40 is providedon the side of the back surface (the side of the second electrode) onthe other side thereof.

As illustrated in FIG. 6B, for example, the rectangular-shaped lightemitting surface is formed as a whole by combining the plurality ofopaque light emitting panels 12 and one sheet of the transparent lightemitting panel 14 in the tiled arrangement.

The region in which the plurality of opaque light emitting panels 12 arearranged is the opaque region illustrated in cross-hatching in FIG. 6B.In the opaque region, the light directed from the light emitting layerto the side of the back surface (the side of the ceiling) is reflectedin the second electrode and then is taken out from the light take-outsurface of the side of the first electrode.

For example, the region in which the transparent light emitting panel 14is disposed is the transparent region having transparency to infraredradiation, visible light or the like. For example, a receiving section45 of the transmitting signal of the remote controller that operates thelighting apparatus 4 is disposed on the back side of the transparentlight emitting panel 14. It is possible to transmit the transmittingsignal of the remote controller by transmitting through the transparentlight emitting panel 14 from the lower side of the lighting apparatus 4with respect to the receiving section 45 thereof.

Particularly, in the embodiment, since the receiving section 45 isdisposed on the side of the back surface of the transparent lightemitting panel 14 performing one-side emission and having transparency,the receiving section is very desirably disposed. That is, thetransparent light emitting panel 14 is a panel which is transparent whennot lighted and in which the light radiates on the side of the surfacethat is the light take-out side but the light does not radiate on theside of the back surface that is the side of the apparatus body 40 whenlighted. Thus, the light of the transparent light emitting panel 14 doesnot radiate on the receiving section 45 and it is possible to suppressthe reduction of reception sensitivity of the infrared radiation or thelike of the receiving section 45 and degradation of the receivingsection 45 by the light thereof. Further, it is possible to suppress theloss of the light amount.

Otherwise, as the receiving section 45, it is also possible to disposethe receiving section of the human sensor, the brightness sensor or thelike on the back side of the transparent light emitting panel 14. It ispossible for the receiving section 45 of the human sensor, thebrightness sensor or the like to detect a human or brightness on thelower side of the lighting apparatus 4 through the transparent lightemitting panel 14.

It is possible to reduce the planar size of the entirety of the lightingapparatus 4 by providing the various receiving sections 45 in a positionsuperimposed on the light emitting panel without providing the receivingsection 45 on the outside of an arrangement region of the light emittingpanel. Particularly, the receiving section 45 is provided within theregion of the apparatus body 40 and the transparent light emitting panel14 is also preferably provided in such a way that at least a part of thetransparent light emitting panel 14 is positioned within the region ofthe apparatus body 40 according to the position of the receiving section45.

According to the fourth embodiment, almost all of the light emittingsurface is the opaque region of the one-side emission and the lightdirected from the light emitting layer to the side of the back surfaceis reflected in the second electrode. That is, it is also possible forthe light that is emitted to the side of the back surface to be derivedto the lower side in the opaque region and the lighting is efficient.Furthermore, even if the receiving section 45 is disposed on the backside of the light emitting panel, it is possible for the receivingsection 45 to receive (detect) the external information from the lowerside of the panel by making a part thereof be the transparent region.

In the lighting apparatus of the embodiments described above in which aplurality of panels are combined, all of the one-side transmissionpanel, the both-side transmission panel and the non-transmission panelmay be combined.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A light emitting panel comprising: an organiclayer including a light emitting layer; a transparent first electrodeprovided on one surface of the organic layer; and a second electrodeprovided on the other surface of the organic layer, and including anopaque first metal film section, and a second metal film section havinga film thickness thinner than a film thickness of the first metal filmsection and light transparency higher than light transparency of thefirst metal film section.
 2. The panel according to claim 1, wherein thefirst metal film section has reflectivity to the light emitted from thelight emitting layer higher than reflectivity of the second metal filmsection.
 3. The panel according to claim 1, wherein the first metal filmsection has transmission of 20% or more at a wavelength of 550 nm andthe second metal film section has transmission less than 20% at thewavelength of 550 nm.
 4. The panel according to claim 1, wherein thefirst metal film section and the second metal film section areintegrally provided with the same metal film.
 5. The panel according toclaim 1, wherein the first metal film section and the second metal filmsection are an Ag film or an Al film.
 6. A lighting apparatuscomprising: a light emitting panel including an organic layer includinga light emitting layer, a transparent first electrode provided on onesurface of the organic layer, and a second electrode provided on theother surface of the organic layer, and including an opaque first metalfilm section, and a second metal film section having a film thicknessthinner than a film thickness of the first metal film section and lighttransparency higher than light transparency of the first metal filmsection; an opaque light emitting panel in which one side surface of anorganic layer including a light emitting layer has light transparencyand the other side surface of the organic layer is opaque; and anapparatus body holding the light emitting panel and the opaque lightemitting panel.
 7. The apparatus according to claim 6, wherein the firstmetal film section has reflectivity to the light emitted from the lightemitting layer higher than reflectivity of the second metal filmsection.
 8. The apparatus according to claim 6, wherein the first metalfilm section has transmission of 20% or more at a wavelength of 550 nmand the second metal film section has transmission less than 20% at thewavelength of 550 nm.
 9. The apparatus according to claim 6, wherein anopaque region is formed by combining a region in the light emittingpanel in which the first metal film section is provided and the opaquelight emitting panel, the apparatus body is superimposed on the opaqueregion, and at least a part of a transparent region where the secondmetal film section is provided in the light emitting panel is notsuperimposed on the apparatus body.
 10. The apparatus according to claim6, wherein the first metal film section and the second metal filmsection are integrally provided with the same metal film.
 11. Theapparatus according to claim 6, wherein the first metal film section andthe second metal film section are an Ag film or an Al film.
 12. Theapparatus according to claim 6, further comprising: a receiving sectionprovided in a position superimposed on a transparent region in which thesecond metal film section is provided, and receiving externalinformation through the transparent region.
 13. The apparatus accordingto claim 12, wherein the receiving section is a receiving section of atransmitting signal of a remote controller that operates the lightingapparatus, a receiving section of a human sensor or a receiving sectionof a brightness sensor.
 14. A lighting apparatus comprising: atransparent light emitting panel in which both surfaces of an organiclayer including a light emitting layer have light transparency; anopaque light emitting panel in which one side surface of an organiclayer including a light emitting layer has light transparency and theother side surface of organic layer is opaque; and an apparatus bodyholding the transparent light emitting panel and the opaque lightemitting panel.
 15. The apparatus according to claim 14, wherein theapparatus body is superimposed on the opaque light emitting panel, and aregion of at least a part of the transparent light emitting panel is notsuperimposed on the apparatus body.
 16. The apparatus according to claim14, further comprising: a receiving section provided in a positionsuperimposed on the transparent light emitting panel and receivingexternal information through the transparent light emitting panel. 17.The apparatus according to claim 16, wherein the transparent lightemitting panel is an one-side emission panel in which one surface emitsthe light, and the receiving section is disposed on the side of anon-light emitting surface of the one-side emission panel.
 18. Theapparatus according to claim 16, wherein the receiving section is areceiving section of a transmitting signal of a remote controller thatoperates the lighting apparatus, a receiving section of a human sensoror a receiving section of a brightness sensor.